Cell Phone Jammers – Myth or Reality?

We’ve all heard that rumors that our Presidental entourage uses a cell phone jammer whenever he’s out and about. We’ve also heard that some big shot embassies use cell phone jammers to thwart security threats. Well, it begs to question – are cell phone jammers real or is it just a myth? Well, you probably guessed it already – Yes they are very real, and illegal for the average Joe.

Illustration of Signal Jamming (Image Credit: HowStuffWorks)

These jamming devices were originally developed for law enforcement and the military to interrupt communications by criminals and terrorists. Other creative uses these days are in religious houses of worship, large hospitals to avoid cell phones interference with sensitive equipment although the 21st century has seen the development of cell phone alerters that produce cell phone proximity alerters instead of actual jamming.

Cell Phone Jamming Notoriety

Cell phone jammers are being used notoriously of late. Just last week, a Chinese company was fined a whopping $34 million by the FCC (Federal Communications Commission – USA) because of its continued supply of cell phone jammers. Last month, another wallet burning $48K fine was given to a motorist who was using a cellphone jammer along a highway from his car in the states. In Africa, however, ordinary cellphone jamming usage will most likely remain relatively low because mobile phone penetration and literacy levels are still relatively low.

How Do They Work?

When you make a call, the signal will be blocked and the caller will hear his/her own voice or a call drop. Cell based trackers e.g car trackers can also be blocked

The average cell phone jammer works at GSM800 frequency because majority cell phones use this darling frequency to operate although some more sophisticated jammers may be tuned for individual frequencies.
The main electronic components of a jammer are:

cell phone jammer circuitry

Voltage-controlled oscillator– Generates the radio signal at 800Mhz that will interfere with the cell phone signalTuning circuit – Controls the frequency at which the jammer broadcasts its signal by sending a particular voltage to the oscillatorNoise generator – Produces random electronic output in a specified frequency range to jam the cell-phone network signal (part of the tuning circuit)RF amplification (gain stage)– Boosts the power of the radio frequency output to high enough levels to jam a signal
Smaller jamming devices are battery operated. Some look like cell phones and use cell-phone batteries. Stronger devices can be plugged into standard power outlets

All these components are available on the local market and since every jamming device has an antenna to send the signal, an old cell phone protruding antenna can be used. With some semi-professional Radio Frequency testing tools and average RF skills, one can feasibly create one. Please do not try this at home.

Making your own Jammer

Unsurprisingly so, several Do It Yourself guides exist out there and I’ve come across numerous websites, which I shall not be mentioning here for obvious reasons, which detail all the necessary info, detailed schematic diagrams, pictures, video with step by step guides to create your own functional cell phone jammer. Please don’t get me started on Wi-Fi Jammers. Sigh!! – The Internet will surely be the death of us.

I have to admit the little techie ghost that haunts me day in, day out tempted me to go through one of these DIY guides and create my own cell phone jammer as a weekend project, but I restrained from it because I don’t want the Uganda Communication’s Commission (UCC) knocking at my door. No thank you.

Very insightful article and of course I knew the president uses one because one time my phone wasn’t working while he was around. Just for curiosity purposes I wanna build my own jammer. Let me start digging up those DIY articles